spec VS wit-bindgen

You can parse many things from this file, what are you trying to extract?

https://github.com/WebAssembly/spec/blob/main/document/core/...

Still strikes me as super sad JS never got SIMD support. It seemed like there were some strong candidate specs. On Node there are some add-on npm libraries that implement.

My understanding was the main protest was that we would get wasm & some certain implementers said they wanted to focus their energy on wasm.

That was well over half a decade ago & wasm is still in incredible infancy, with basically only statically linked capabilities in the spec.

Wasm SIMD proposal itself only merged into wasm in November 2021. https://github.com/WebAssembly/spec/pull/1391

It seems really unfortunate to have decided to keep JS the slow inferior language.

Blazor and WASM itself (outside of dotnet) are relatively new tools and they already show impressive results. They will keep getting better with every release. E.g. this proposal https://github.com/WebAssembly/spec/blob/main/proposals/simd/SIMD.md which should bring WASM closer to "near native speed". Blazor already started working on it true.

Big fan of this author's work.

They have a Gameboy emulator written in C, which can be compiled to WASM and run in the browser.

https://github.com/binji/binjgb

I learned a lot from the code.

Also I love this project with a bunch of demos in hand-written WebAssembly Text (WAT) format, which is like low-level Lisp that works only with raw memory, numbers, and minimal syntax.

https://github.com/binji/raw-wasm

Then I discovered the same author is quite active in the WebAssembly ecosystem, including specs and tooling. Fascinating stuff!

https://github.com/WebAssembly/spec

https://github.com/WebAssembly/wabt

[The WebAssembly specification (https://webassembly.github.io/spec/) maintains that the standards apply to more than just the browser host, but also to any other compliant host runtime (what the specification refers to as an embedder).

Heya,

(1) Thank you for implementing this in JSC!! I hope they take it, it makes it into Safari, and the tail-call proposal advances.

(2) I don't think you are exactly right about the call stack being observable via thrown exceptions. There's no formal spec for the v3 exceptions proposal yet, but in the documents and tests, there's nothing that would change in WebAssembly core to make the call stack observable. It's true that the proposal amends the JS API (but only the JS API) to describe a traceStack=true option; from Wasm's perspective I understand that's just an ordinary exception that happens to include an externref value (just like any other value) to which Wasm itself attaches no special significance. The engine can attach a stack trace if it wants, but there's no requirement (here) about what that stack trace contains or whether some frames might have been optimized out.

(3) I think the real reason that a Wasm engine can't implicitly make tail calls proper is that the spec tests forbid it, basically because they didn't want the implementation base to split by having some engines perform an optimization that changes the space complexity of a program, which some programs would have started to depend on (the spec tests say: "Implementations are required to have every call consume some abstract resource towards exhausting some abstract finite limit, such that infinitely recursive test cases reliably trap in finite time. This is because otherwise applications could come to depend on it on those implementations and be incompatible with implementations that don't do it (or don't do it under the same circumstances.)" More discussion here: https://github.com/WebAssembly/spec/issues/150

The WASM paper discusses that in the final section: https://github.com/WebAssembly/spec/blob/master/papers/pldi2017.pdf

WebAssembly has a formal specification that includes both operational semantics and natural language-based descriptions of everything in the language. The official repository also has a lot of tests. Besides tests, you should be able to find lots of examples by searching.

The component model is already shipping in Wasmtime, and will be stable for use in Node.js and in browsers via jco (https://github.com/bytecodealliance/jco) soon. WASI Preview 2 will be done in December or January, giving component model users a stable set of interfaces to use for scheduling, streams, and higher level functionality like stdio, filesystem, sockets, and http on an opt-in basis. You should look at wit-bindgen (https://github.com/bytecodealliance/wit-bindgen) to see some of the languages currently supported, and more that will be mature enough to use very soon (https://github.com/bytecodealliance/componentize-py)

Right now jco will automatically generate the JS glue code which implements a Component Model runtime on top of the JS engine's existing WebAssembly implementation. So, yes, Components are a composition of Wasm Modules and JS code is handling passing values from one module/instance to another. You still get the performance benefits of running computation in Wasm.

One day further down the standardization road, we would like to see Web engines ship a native implementation of the Component Model, which might be able to make certain optimizations that the JS implementation cannot. Until then you can consider jco a polyfill for a native implementation, and it still gives you the power to compose isolated programs written in many languages and run them in many different contexts, including the Web.

(Disclosure: I am co-chair of WASI, Wasmtime maintainer, implemented many parts of WASI/CM)

Thank you!

To your point, the primary consideration for choosing the languages is their support for WebAssembly, and WASI in particular.

Due to Spin's heavy use of WASI and the component model, languages that have first party support in the WIT bindings generator (https://github.com/bytecodealliance/wit-bindgen) are the easiest to implement, followed by languages that can be built on top of the support for those with first party support.

For example, the JavaScript support is built by embedding QuickJS (in particular, Shopify's Javy project — https://github.com/fermyon/spin-js-sdk), which then uses the Rust SDK.

There are many options, but what worked best for me is compiling with cargo-wasi and loading the resulting Wasm file with browser_wasi_shim. Using wasm32-wasi instead of wasm32-unknown-unknown requires a bit more work (the communication with JS has to be set up manually), but gives the flexibility of having just a Wasm file that can be dropped in and loaded dynamically. (There's wit-bindgen for generating wrapping code according to an interface definition but I didn't have much success with it.)

I've been playing with creating a go version of the abi for use with wit-bindgen because the current one uses cgo https://github.com/bytecodealliance/wit-bindgen

wit-bindgen - Language Binding Generator for WASM Interface Type

wit-bindgen-rust = { git = "https://github.com/bytecodealliance/wit-bindgen.git", rev = "60e3c5b41e616fee239304d92128e117dd9be0a7" }

Yep, you're right. For this, there are a few options. The ones most relevant to you are fp-bindgen, which targets Wasmer, and wit-bindgen, which targets wasmtime.

Are you evaluating if WebAssembly Component Model, its WIT format and related tooling like wit-bindgen could be a good fit for your multiple languages support?

[package] name = "sentiment" version = "0.1.0" edition = "2021" # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html [dependencies] wit-bindgen-rust = { git = "https://github.com/bytecodealliance/wit-bindgen.git", rev = "60e3c5b41e616fee239304d92128e117dd9be0a7" } vader_sentiment = { git = "https://github.com/ckw017/vader-sentiment-rust" } lazy_static = "1.4.0" [lib] crate-type = ["cdylib"]